A variety of coil innerspring assemblies have been developed within the industry and have been in use for a number of years. Some of these coil innerspring assemblies are comprised of a number of coil springs that are individually encased within an outer spring pocket to form a corresponding number of pocketed coil springs. The spring pockets are typically fabricated by providing a sheet of fabric material that is folded approximately in half with transverse cross seams formed along the height of the spring pocket. The cross seams are spaced apart a distance somewhat greater than the outer diameter of the coil spring to form an appropriately sized spring pocket. A coil spring is inserted into the sleeve pocket and the overlapping edges of the sheet are attached together by a longitudinal seam to close the spring pocket.
In some instances, a series of the pocketed coil springs are interconnected to form an integral/continuous strip or string of pocketed coil springs. One example of a method for forming continuous strips of pocketed coil springs is illustrated and described in U.S. Pat. No. 6,398,199 to Barber, the contents of which are hereby incorporated herein by reference. The strings of pocketed coil springs may be coupled together to form a complete coil innerspring assembly.
One example of a method for coupling together strings of pocketed coil springs to form a complete innerspring assembly is illustrated and described in U.S. Pat. No. 6,398,199 to Barber. Top and bottom securing sheets or “scrims” may be used as a means for interconnecting strings of pocketed coil springs. The top and bottom scrims are secured to the upper and lower surfaces of the pocketed coil springs by an adhesive or other suitable means of attachment. However, the use of top and bottom scrims tends to increase material costs and the labor costs associated with securing the scrims to the pocketed coil springs.
Other methods have also been used to couple together individual pocketed coil springs or strings of pocketed coil springs. For example, rings or ties have been used to interconnect adjacent pocketed coil springs. Additionally, stitching or sewing techniques have been used to interconnect adjacent strings of pocketed coil springs. However, the labor costs associated with these methods of interconnection can also be significant.
While advances have been made in the industry, there is a continuing need for improved coil innerspring assemblies, particularly with regard encased coil innerspring assemblies formed of strips or strings of pocketed coil springs that are coupled together to form a complete encased coil innerspring assembly. The present invention meets this need and provides other benefits and advantages in a novel and unobvious manner.